Thews



UNITED STATES PATENT OFFICE.

\VILLIAM H. MATHEWS, CHARLES W. AYEES, AND MADISON D. CAMPBELL,

. OF BODIE, CALIFORNIA.

COMPOUND FOR FACILITATING THE AMALGAMATION OF GOLD AND SILVER.

SPECIFICATION forming part of Letters Patent No. 242,669, dated' June '7', 1881. Application filed July 20, 1880. (No specimens.)

To all whom it may concern:

Be it known that we, WILLIAM H. C. MA- THEWS, CHARLES W. AYRES, and MADISON D. CAMPBELL, of Bodie, in the county of Mono and State of California, have invented a new and Improved Compound for Facilitating the Al'nalgamation of Gold and Silver, of which the following is a specification.

It is well known to workers of gold and silver ores that the pan-amalgamation process always results in a very considerable loss of the precious metals and of the quicksilver, the loss of the former bein g in a great measure due to the fact that the particles of metal are coated with some substance that repels the quicksilver or prevents its contact with the metal,

and the loss of the quicksilver being principally due to the flouring of the latter, because of its trituration in the pans and because of the presence of certain interfering mineral substances that coat the globules of quicksilver and prevent their reunion.

The object of this invention is to provide a cheap and effective compound to he used in the amalgamatin g process for preventing this loss of both the gold and silver and the quicksilver by brightening the particles of the precious metals and by preventing the coating of the quicksilver globules.

It is well known that common salt in some instances, and in other instances soda, have been used in amalgamating-pans to accomplish the desired purpose, and that these salts produce a greater or less beneficial effect, according to'the quality of the ore operated upon, the partial decomposition of the salts and the combination of their elements in some degree with the interfering mineral substances operating to diminish the otherwise large percentage of loss in the common amalgamatingpans.

It-is also well known that sodium amalgaman unstable compound of sodium and quicksilverhas been successfully used in the amalgamating process to save the precious metals and quicksilver; but the cost of the sodium amalgam and the difficulty of keeping it always in condition prohibits its extensive use.

We have discovered a saline compound that is open to none of the objections that apply ride, sixteen (16) per cent; calcium chloride and carbonate, eight (8) per cent. and sodium borate, two (2) per cent. The proportions of these salts may vary slightly under certain conditions; but in all cases the compound we use to facilitate pan-amalgamation contains all the above-named salts, and in about the proportions set forth.

The quantity of the compound used to the ton of ore depends upon the character of the ore; but in all instances it is found that the mixture of a certain quantity of this compound with the ore and quicksilver in all amalgamating-pans results in prey'enting the flouring of the quicksilver, and in the cleansing or brightening of the precious metals, and that consequently a saving of from five to ten per cent. of quicksilver and from five to ten per cent. of the assay value of the precious metals is made over the ordinary method of amalgamatiug.

In the presence of this saline compound in the amalgamating-pan the quicksilver retains its brightness, liquidity, and cohesiveness, and

WILLIAM H. C. MATHEWS. CHARLES \V. AYRES. MADISON D. CAMPBELL.

Witnesses:

A. SonERLINe, E. J. HEINs. 

